GOBO database analysis indicated that PTEN is highly expressed in luminal breast cancer cell lines (P = 0.0186), specifically in the luminal A patients (P < 0.00001) and ER-positive subtypes patients (P = 0.0106) (Fig. S1a–c).To further explore Notch3 and PTEN expression, we performed immunofluorescence staining for Notch3 and PTEN in MCF-7 and T-47D cells. This evidence concerns the gene ESR1 and breast cancer.